The Gettysburg National Military Park is an administrative unit of the National Park Service's northeast region and a subunit of federal properties of Adams County, Pennsylvania, with the same name, including the Gettysburg National Cemetery. The GNMP properties include most of the Gettysburg Battlefield, many of the battle's support areas during the battle (e.g., reserve, supply, & hospital locations), and several other non-battle areas associated with the battle's "aftermath and commemoration". The administrative unit also manages the adjacent Eisenhower National Historic Site subunit and displays a portion of their 43,000 American Civil War artifacts in the Gettysburg Museum and Visitor Center.

The park has more wooded land than in 1863, and the National Park Service has an ongoing program to restore portions of the battlefield to their historical non-wooded conditions, as well as to replant historic orchards and woodlots that are now missing. In addition, the NPS is restoring native plants to meadows and edges of roads, to encourage habitat as well as provide for historic landscape. There are also considerably more roads and facilities for the benefit of tourists visiting the battlefield park.